Shi'ite Militias Strike West of Mosul to Cut Off ISIS Retreat Routes

Children who just fled Abu Jarbuah village sit at a Kurdish Peshmerga position between two front lines near Bashiqa, east of Mosul, Iraq, October 29. Zohra Bensemra/Reuters

Iraqi Shi'ite militias said on Saturday they had launched an offensive toward the west of Mosul, an operation that would tighten the noose around the Islamic State militant group's (ISIS) Iraq stronghold but could inflame sectarian tension in the mainly Sunni region.

The battle for Mosul is expected to be the biggest in the 13 years of turmoil unleashed in Iraq by the 2003 U.S.-led invasion which toppled former president Saddam Hussein, a Sunni Muslim, and brought Iraq's majority Shi'ite Muslims to power.

A spokesman for the Shi'ite militias, known as the Hashid Shaabi (Popular Mobilisation) forces, said thousands of fighters "started operations this morning to clean up the hotbeds of Daesh (Islamic State) in the western parts of Mosul."

The city is by far the largest held by the ultra-hardline Sunni ISIS and its loss would mark their effective defeat in Iraq, two years after their leader Abu Bakr al-Baghdadi declared a cross-border caliphate in parts of Iraq and neighboring Syria from the pulpit of a Mosul mosque.

The Shi'ite militias aim to capture villages west of Mosul and reach the town of Tal Afar, about 55 km (35 miles) from the city, the Hashid spokesman said. Their goal is to cut off any option of retreat by ISIS insurgents into neighboring Syria or any reinforcement for their defense of Mosul.

The Iran-backed and battle-hardened paramilitaries bring additional firepower to the nearly two-week-old campaign to recapture Iraq's second largest city from the jihadist group.

Iraqi soldiers and security forces and Kurdish peshmerga fighters, backed by a U.S.-led air coalition and thousands of Western military personnel, have been advancing in the last 13 days on the southern, eastern and northeastern fronts around Mosul, which remains home to 1.5 million people.

The United Nations has warned of a possible humanitarian crisis and a potential refugee exodus from Mosul—though the start of operations on the city's western flank could leave Mosul's civilians with no outlet to safety, even if they are able to escape ISIS control.

Villagers from outlying areas around Mosul have told Reuters that women and children were being forced to walk as human shields alongside retreating Islamic State fighters as they withdrew into the city this week.

Iraqi and Western military sources say there had been debate about whether or not to seal off Mosul's western flank. Leaving it open would have offered ISIS a chance to retreat, potentially sparing residents from a devastating, inner-city fight to the finish.

Some civilians fleeing Mosul have used the roads to the west to escape to Qamishli, in Kurdish-controlled northern Syria. Others, from villages just outside Mosul, have exploited the chaos to flee in the other direction.

"Some people fled the other day so we took a chance. Daesh fired two bullets at us but they missed and we made it," said Ahmed Raad, 20, from the village of Abu Jarbuaa northeast of Mosul, who had found refuge at a peshmerga base.

The International Organisation for Migration said on Saturday 17,520 people have been displaced so far during the Mosul operation—excluding thousands of people forced back into the city by Islamic State.